An infrastructure-based wireless network typically includes a communication network with fixed and wired gateways. Many infrastructure-based wireless networks employ a mobile unit or host which communicates with a fixed base station that is coupled to a wired network. The mobile unit can move geographically while it is communicating over a wireless link to the base station. When the mobile unit moves out of range of one base station, it may connect or “handover” to a new base station and starts communicating with the wired network through the new base station.
In comparison to infrastructure-based wireless networks, such as cellular networks or satellite networks, ad hoc networks are self-forming networks which can operate in the absence of any fixed infrastructure, and in some cases the ad hoc network is formed entirely of mobile nodes. An ad hoc network typically includes a number of geographically-distributed, potentially mobile units, sometimes referred to as “nodes,” which are wirelessly connected to each other by one or more links (e.g., radio frequency communication channels). The nodes can communicate with each other over a wireless media without the support of an infrastructure-based or wired network. Links or connections between these nodes can change dynamically in an arbitrary manner as existing nodes move within the ad hoc network, as new nodes join or enter the ad hoc network, or as existing nodes leave or exit the ad hoc network.
Recently, there has been a growing interest in the integration of wireless networks. Examples of integrated networks include Advanced Mobile Phone Service (AMPS) combined with IS-95 cellular networks, Global Positioning System (GPS) applied in cellular networks, combined satellite and cellular networks, and combined cellular and wireless local area network (LAN) networks.
Recently, the integration of cellular networks and ad hoc networks is also gaining interest. It will be appreciated that the construction of ad hoc networks is dependent on an adequate density of ad hoc devices. It will further be appreciated that in an area where there is sufficient density of handsets capable of joining an ad hoc network, there may be a variety of handset manufacturers and a variety of handset service providers. One problem in this environment is that each service provider is not accustomed to participating or cooperating with other service providers. Therefore, any attempt to establish an ad hoc network that contains handsets from multiple service providers is likely to be blocked. One reason for blocking the ad hoc formation is concern for security of the service provider's subscribers and concern for unauthorized use of services provided by the service provider (e.g. a game or email service).
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.